The problem is, my terminal already has a concept of scrolling, and its own concept of a buffer, with its own concept of keeping unlimited contents based on available memory, etc.

I've never seen a tmux setup that doesn't fail horribly when these two concepts collide (I can't cmd-f search the buffer for interesting things, I don't get a scroll bar on the right that shows me how far up the buffer I am, scroll acceleration doesn't work, etc.)

Terminal.app already does split panes, tabs, scroll acceleration, search, etc. I don't get persistence, but I don't really understand the workflow where you'd want it. I typically open new tabs exactly because I want a fresh workspace, and I close them exactly because I want to clear my workspace. I can just manually call tmux when I know the thing I'm running should outlast a window (and actually, 99% of the time that's on a server I'm SSH'd into, not on my local machine.)

Can anyone convince me why I need to be all-tmux all-the-time?